Toxoplasma gondii infection in cancer patients in Guilan, Iran: prevalence and risk of acquired or reactivation of latent Toxoplasmosis

Introduction: Toxoplasma gondii (T. gondii) infection in immune-compromised individuals, including malignant patients under chemotherapy, can cause severe diseases as encephalitis or systemic infections. There is no study on toxoplasmosis in cancer patients in Guilan Province.This study was designed to determine toxoplasmosis IgM and IgG antibodies in cancer patients and to compare it to normal population in the north of Iran, Guilan. Materials and methods: The present case control study is the first study on the prevalence of toxoplasmosis in cancer patients referred to an educational hospital in Rasht- Guilan (North of Iran), from July 2017 to January 2018. The range of the participants' age was 14–88 years, of whom 52.6% and 47.4% were male and female, respectively. Blood samples were collected from 150 immunocompetent individuals as a control group and 150 cancer patients. The antibodies (IgG/IgM) were measured by the ELISA method using available kits (ToxoIgG and ToxoIgM Euroimmun). Results: The overall sero-prevalence of toxoplasmosis among the participants was 96 (64%) and 97/150 (64.7%) in cancer patients and controls, respectively. In patients, 94 (62.6 %%) were seropositive for only IgG, 1 (0.66%) for only IgM, and 1 (0.66%) for both IgG and IgM. In the control group, 1/150(0.66%) had IgG and IgM positive and 96/150 (64 %) were IgG positive and IgM negative that considered acute and chronic toxoplasmosis, respectively. Two out of 150 control groups were IgG and IgM borderline, respectively. This difference was not statistically significant for IgG (P= 0.8) and IgM (P=0.85) among the patients and also the control groups. Sero-prevalence of T. gondii infection varied significantly with age, sex, residence, cat at home, and educational level. Conclusion: The data showed that a high percent of patients and control groups were susceptible to re-activation of latent toxoplasmosis. But In immune-compromised patients, reactivation of latent toxoplasmosis could even leads to lethal encephalitis. Therefore, the screening of toxoplasmosis should be considered more routinely in cancer patients.